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Discussion Starter #1
Got the dreaded code 69 this past week, temp has been running about 1/4th on the gauge the past few days. Already had a new t-stat on hand with o-rings, so dived into it this morning. Total R&R time was about 1.5 hours, had to run out and get some distilled water to mix with the coolant. Only took apart things absolutely necessary, which seemed to make the job go easier. Replaced one of the big o-rings, which had a couple indentations on it. Re-used the other large one and the small ones. So far looks like everything is fine. It's a little tricky getting the housing out, but this job really isn't very difficult. It was easier for me to put the housing back in versus getting it out. The car has 99k miles on it, I assume it was the original t-stat.
 

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Congrats caspian. Were new o-rings that expensive? ;) Hopefully there's no problem because of that.

Wait till everyone finds out I did my 96k front shock job and replaced nothing but the shocks! :eek:oohhh:
 

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Wirelessly posted (Mozilla/5.0 (Linux; U; Android 2.2; en-us; Droid Build/FRG22D) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1)

Personally, I wouldn't risk at least an hour worth of labor to save 5 dollars on rubber parts that are basically guaranteed to fail, but whatever works for you. :)
 

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This might be OT, but do you guys do water pump replacements as preventative maintenance also?? I noticed the part is a whopping $475!!

Just curious.. thanks!
 

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Sorry dude. Although i agree with the point that whilst its off, $4 worth of o rings would be good for a belt and braces job i can't for the life of me see how a static O ring is "guaranteed to fail".

Once installed it doesn't move at all unless you take the stat housing out again. The rubber they are made of doesn't get brittle like say vanos o rings because its not in contact with oil at any point. I'm willing to bet that if the Tstat was of a better design whereby it didn't need replacing ever, then your o rings would never fail for the life of the car.

I agree its good practice but don't slate someone for reusing parts that are good.

There are far too many people on this board that just want to repeatedly throw parts at their Beasts for the sake of doing so.

Whilst i am all for preventative maintenance, even down to sensors that are coming to the end of their service life, but are not showing signs of malfunction, i think if you have a sensible attitude regarding any replacement of parts as opposed to going to the dealers with a bag of cash just because someone else happened to have a similar problem on half the mileage, and buying the whole page of REALOEM, it should be applauded, not ridiculed.

To the OP. Well done, not a bad job really is it. Did you take the plenum off for access or do it with it in situ?
 

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I replaced my thermostat and waterpump over the past 2 weeks.
I had a failing water pump - loss of coolant through the tell-tale and screaching noises. So looked up how to do everything on his board - fantastic help-

BUT

Stripped everything down (having bought the new parts and torx bolts for the vibration damper).
Took of viscous coupled fan - no problem.
Rotated engine so i could put a peg in the vibration damper (actually quite important - thanks for that tip).
Removed the Crank pulley - no problem.
Removed first 3 torx bolts holding the vibration damper on (you have to do this to get at the last bolt on the water pump) - and these bolts are recessed in about 1 inch into a small hole in the centre of the vibration damper) - all going well

THEN

final bolt would not move no matter what i did - eventually stripped the head - bought lots of tools to try to get it off - no success. So now to drill it out - however this required removal of the fan guard and radiator and buying a drill small enough to fit in the space - OMG. Finally drilled a 7 mm hole through the bolt head - so thought "ah i will use one of those thick extractor screws" - wish i hadn't - it snapped off leaving the hole completely filled with a bit of very tough extractor screw that i could not drill through. If anyone has seen the size of the hole the bolts are in you will understand that not many tools will fit in there - so i went through 15 dremel cutting disks - a burnt out dremel - finally after 18 hours of work and another 12 drill bits the head snapped off - leaving the vibration damper free and the remainder of the bolt sitting proud so that i could unscrew with my fingers.

Putting it all back together was easy - vasoline on the o-rings - perfect - not a leak and took less thatn 1 hour to put everything i had removed back on. Thanks for the board for the info - but i hope no one has the nightmare i had.

So with 275,000 miles on the clock i have now taken it to my friendly car restorer (who has worked on some of my other cars) to have every bit of rust, dings and scratches taken out - the interior still looks like new - so hoping it will come back perfect for my trip across Europe to some of the Christmas Markets in early December.
 

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mate that sound a serious ballache. Props for sticking with it. I've had a good few 2 hour jobs that turn into a weekender because of stuff like that. Did you mount the new screws with copperslip or such to stop it happening again?
 

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No - would not risk copperslip - the bolts are one time only (they are meant to stretch i think) - done up to 60mn then 2 x 50 deg.

Hopefully won't be doing that again in a hurry. From reading on here i thought the hardest part would be getting the o-rings and tubes connected on the thermostat - but went in easily (of course having the whole lot off helps you understand exactly how they work.
Anyway did a few hundred miles without problems then dropped off for it's makeover.

Actually ncie feeling when done - and certainly made me more confident about tackling other jobs as they arise. I have had enough of BMW prices for fixing stuff. Mind you the water pump was very expensive - £400ish - oh but they gave me £70 back when i returned the old pump - thanks BMW - even the parts guy was laughing at how much they charged for the pump and gaskets - said he couldn;t believe it.
 

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Discussion Starter #11
To the OP. Well done, not a bad job really is it. Did you take the plenum off for access or do it with it in situ?

I didn't take the plenum off, here's what I R&R'd:

-Remove air intakes to plenum, did not unplug MAF's, just put them to the side
-Remove 2 hoses going to t-stat housing
-Remove oil piece junction on top of housing, not sure what it's called. Removed the oil lines only on the driver side
-Removed temp sensor
-Loosened hose clamp on hose at base of plenum, gave me a little extra clearance

I ended up using some lithium grease on the o-rings, the amber type, not white. I knelt in front of the car and could see exactly where the 3 pipes needed to go. Re-positioned the t-stat once and everything just slipped back together. I was surprised how easy it was, especially after reading about problems here.
 

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Me too regarding putting it back together. I guess the hard part is making sure you are as straight as possible before trying to push the assembly home.

I never took the plenum ff either, but was suprised to hear that the TIS recommends that. I just wondered if it was that much easier with taking it off. I took around an hour and a half start to finish, taking my time.

Funny that, as it was one of the first jobs i tackled on the Beast which gave me the confidence to treat it as just another engine also.
 

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Rubber degrades over time, due to heat, friction and presumably some contact with the coolant (not much, but some). OP is correct, it's not a difficult job, but if you're miles from home and suddenly spring a coolant leak, that $5 saved is going to probably seem pretty expensive.

Like I said, whatever works for folks :D Nice job on the replacement.

Cheers!
 

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Sorry mate i don't agree.

If you don't spring a leak from the o rings when you first do the stat change, you are not going to experience a coolant leak from there.

Yes, rubber can degrade over time but not like what you are saying. If coolant was a substance that degraded rubber, then maybe everyone who owns any type of car on the planet should be looking to replace every hose in their coolant system as these are rubber and are in constant contact with coolant throughout their life.

Dude, i agree with you in that its good practice to change the o rings, but it just grinds my gears a bit when someones posting about a succesful DIY on their car, and the first thing that pops to mind is "oh you haven't changed the other 5,000 components that are in the surrounding 4 feet of the stat also"

Theres no need for any tongue in cheek snide comments like "well you did it the wrong way but hey, whatevers good for you" at all in these threads.

If the guy had built it up and it leaked, and he hadn't bought any o rings to be ready for that in case he nipped one on rebuilding it, then yeah, thats a bit silly. But if he has them and doesn't need to change them then really, what IS the problem exactly???
 

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The problem with the internet, is there's no way to get context or intent through a keyboard. My "whatever works" comment was most certainly not tongue-in-cheek. This is a simple risk-reward decision and people are free to do as they choose. Many people will opt for the safer but slightly more expensive choice, others are comfortable with taking a little risk to save time/money/whatever. As I stated earlier, it's not what I chose when I did my thermostat, but I'm not here to judge anyone for their decisions. I've personally talked to someone that had old coolant o-rings crack without any external influence, so I was trying to save caspian from getting stranded somewhere with a leaking engine. I sincerely hope the system holds up until the next stat change.

If my comment came across as snide, I'm truly sorry. My congratulations on finishing the job was also sincere. I don't think there's anything to gain by further posting, so I'll leave the thread here.



Sorry mate i don't agree.

If you don't spring a leak from the o rings when you first do the stat change, you are not going to experience a coolant leak from there.

Yes, rubber can degrade over time but not like what you are saying. If coolant was a substance that degraded rubber, then maybe everyone who owns any type of car on the planet should be looking to replace every hose in their coolant system as these are rubber and are in constant contact with coolant throughout their life.

Dude, i agree with you in that its good practice to change the o rings, but it just grinds my gears a bit when someones posting about a succesful DIY on their car, and the first thing that pops to mind is "oh you haven't changed the other 5,000 components that are in the surrounding 4 feet of the stat also"

Theres no need for any tongue in cheek snide comments like "well you did it the wrong way but hey, whatevers good for you" at all in these threads.

If the guy had built it up and it leaked, and he hadn't bought any o rings to be ready for that in case he nipped one on rebuilding it, then yeah, thats a bit silly. But if he has them and doesn't need to change them then really, what IS the problem exactly???
 

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@Lothar. OK dude, i've took your comments the wrong way. Sorry for that. Reading my post back i've bit a little there. Sorry.

@Mike, you'd be the expert on that mate not mehiha

Whats going on regarding jobs on your car, is the garage empty of ****e yet?
 

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This might be OT, but do you guys do water pump replacements as preventative maintenance also?? I noticed the part is a whopping $475!!

Just curious.. thanks!
My water pump seized on me about 5 years ago. No warning, no squeaking noises, nothing. Just a very sudden and very loud BANG. The fan belt snapped, taking out the (unfeasibly expensive) tensioner pulley system, and the under bonnet sound proofing. All in the cost was enormous! Apart from that, I had to drive home through traffic without any alternator, power steering, or engine cooling. I just switched her off each time I had to stop. Somehow I made it without overheating or any damage, other than to my biceps. (have you ever tried parking an M5 with no power steering?!) I'd say yes - change it around 100k if you haven't already. I was lucky that the fan, MAF housings etc didn't get smashed up too......

To the OP - good skills. Have you noticed BOTH the oil & water temps sitting higher than before, and the car feeling waaaay better when she's warmed up? :M5thumbs:
 

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Discussion Starter #19
To the OP - good skills. Have you noticed BOTH the oil & water temps sitting higher than before, and the car feeling waaaay better when she's warmed up? :M5thumbs:
Yes, the temp gauge is pointing about exactly in the middle now, it would barely get over 1/3 before. I ran the KTMP display on a 50 mile drive today, temperatures got up to around 85-91 in traffic and then cooled to around 81-85 on the highway. The oil temperature is about the same, haven't really noticed much difference, maybe a tad higher. So far, everything appears to be normal. Turned over 100k miles on the way back home!
 

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Did my change a while back while replacing the valve cover gaskets - so good access.
Replaced as my old one was allowing the temp gauge to get close to the first 1/3 mark.
Yes - I did replace all the old o-rings although the old ones looked fine.

My new thermostat is behaving EXACTLY the same way as the old.

Drive on the HWY - coolant needle just past the 1/3 mark, oil not quite 1/2 way. OBC temps 79-82
Drive in the City - coolant needle 1/2 way, oil just past 1/2 way - OBC temps 87-95
Ambient temps don't appear to affect the needle - whether -2 or +25 C

Thermostat is rated for 79C so I guess the new thermostat is doing the job.

Fuel economy hasn't budged so it really doesn't appear to make a difference.

Used BMW blue coolant, distilled water.
 
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